The invention relates to a fireplace construction, as for application to a residential dwelling.
One of the best fireplaces, to keep warm with minimum consumption of wood fuel, was developed hundreds of years ago, after countless generations of heating with wood. It is still in use today in many of the colder countries of Europe and is aptly known as the Russian Fireplace. The Russian Fireplace is designed around two basic principles: burn the fire hot and fast, and channel the hot flue gases through a mass of masonry designed to absorb the heat. Fire is a conversion process to change into heat the stored energy in the fuel (wood). The hotter the fire, up to about 1200.degree. F., the more efficient this conversion process becomes, and the more stored energy is converted into heat. When the hot flue gases are then channeled through several tons of masonry, through properly-designed flue passages, most of this heat can be absorbed and stored by the masonry. The stored heat will then be radiated into adjacent living space over a period of many hours.
If the Russian Fireplace has been in use so long and is so efficient, why then have its principles not been followed in designing today's fireplaces? And why have we been allowing up to 90 percent of the heat available in wood to be lost via the chimney? The answer is that fuel costs have been relatively cheap, and there has been massive reliance on fuels such as oil which have only recently skyrocketed in price. Stoves have emerged as means of more efficiently using available heat from a wood fire, but the process involves a fully enclosed hearth, so that a bright, cheery fire cannot be viewed.